Nintendo Gamecube USA Missing
From Redump Wiki
All USA GameCube games are believed to be dumped. Additional versions may exist.
Kiosk Demonstration Test Disc Release October 2001 (same as?) Read Check Program [DL-DOL-022E-JPN]
Unlicensed Discs - Action Replay
Unlicensed discs have backup protection on them. Chances are fairly good there's a disc for each version. These discs definitely exist:
Action Replay 1.06 Action Replay 1.08 Action Replay 1.09 Action Replay 1.14a Action Replay 1.14b Action Replay 1.14c Action Replay 1.18 (http://wiird.l0nk.org/forum/index.php/topic,6731.0.html) Action Replay 1.20 (Works on all Wiis) (No code entry function)
Unlicensed Discs - Ultimate Codes
Produced by Datel. Some are called "Action Replay Ultimate Codes:", others are called "Ultimate Codes".
Action Replay Ultimate Codes MAX PACK: Mario Kart Double Dash, Mario Party 4 & 5, Mario Sunshine, Mario Golf Animal Crossing Enter The Matrix Final Fantasy - Crystal Chronicles Mario Kart - Double Dash!! Metal Gear Solid - The Twin Snakes Metroid Prime The Legend Of Zelda - Twilight Princess The Legend of Zelda - The Wind Waker Wario World
Unlicensed Discs - Other
Hopefully not updated as frequently as the Action Replay discs. The exact number of versions is not known.
Freeloader 1.06 SD Media Launcher